1. Field of the Invention
The present invention relates to a camera shaking preventive device and a camera shaking warning device for providing warning when camera shaking occurs.
2. Related Background Art
Among so-called automatic exposure cameras which determine the diaphragm value or shutter speed based on the luminance or the like of the object, there are known cameras capable of following preventive measure for camera shaking:
(1) detecting the presence of camera shaking at the phototaking operation and, in case of camera shaking, selecting a faster shutter speed even for the same object luminance; or
(2) giving a warning to the user if the determined shutter speed is slower than a predetermined limit value for camera shaking (defined in the camera).
When a shutter speed is changed from a slower speed to a faster speed for a same object luminance, the diaphragm value has to be decreased (from a smaller aperture to a larger one) for obtaining an appropriate exposure, so taht the depth of focus is reduced. In the camera of the category (1) explained above, a faster shutter speed is automatically adopted if the camera shaking occurs even only once. Thus, even if camera shaking occurs accidentally at a shutter speed which is normally free from camera shaking, the shutter speed becomes undesirably fast, thus sacrificing the depth of focus.
On the other hand, in the camera of the category (2) explained above, because said limit value is constant, the warning may be given at a shutter speed which does not cause camera shaking for a skilled photographer, thus giving unpleasant feeling to the user.
Thus, these cameras may be inconvenient for certain users, because the camera shaking preventive measures do not take the level of skill of the user into consideration.